include logo in paypal page

Fellows I’m stuck with a problem. I have adaptive payment setup with paypal and the problem is that i’m using the account to received money into the same account from two different sites. I have already set up a logo into paypal account when people uses the site1, for site2 i need to pass a logo to the header dynamically.
The loser of paypal don’t give me a clear answer. I have been trying to use amazon fps but i keep receiving an error with them too. For now i think is easy to stick with paypal. The API and all that is set already. But i can pass my company logo when people is going to pay.

I have this in the code right when the buyer clicks pay…
header(“Location: https://www.paypal.com/webscr?cmd=_ap-payment&paykey=”.$ap);

I’ve been researching that i should maybe pass the header with java? because i don’t see how header can accept another parameter which should be my company logo.
Any help is appreciated.